1. Field of the Invention
The present invention relates to an electrophotographic photosensitive member having a photoconductive layer comprising a resin in which a photoconductive powder is dispersed, and more particularly, to an electrophotographic photosensitive member comprising a deionized resin as a resin for dispersing a photoconductive powder therein to provide improved humidity resistance.
2. Description of the Prior Art
In a photoconductive layer of an electrophotographic photosensitive member there has been used Se, organic photoconductor (OPC) or the like, vapor-deposited on a substrate as well as a paint composed of resins containing photoconductive powders such as CdS, ZnO and the like, dispersed therein, coated on a substrate.
As a binder resin, there may be used a vinyl type, acrylic type, epoxy type resin and the like, in consideration of its electrical or mechanical properties, etc.
One of the most important properties of electrophotographic photosensitive members is resistance to deterioration of chargeability in a high humidity environment. It has been presumed that such deterioration results from the presence or formation of various ions. Particularly, since inorganic photoconductive powders such as powders of CdS, ZnO, TiO.sub.2 and the like, are liable to contain ions remaining from their preparation, a certain deionization treatment is required to improve the resistance to deterioration of the electrical chargeability in a highly humid environment. However, treatment of the powders alone is not always satisfactory.